Site-specific monoPEGylated interferon alpha2a mediated by microbial transglutaminase / 生物工程学报

PEGylation is considered one of the most successful techniques to improve the characteristics of protein drugs including to increase the circulating half-life of proteins in blood and to decrease their immunogenicity and antigenicity. One known PEG modification method is to attach PEG to the free amino group, typically at lysine residues or at the N-terminal amino acid with no selectivity, resulting in a heterogeneous product mixture. This lack of selectivity can present problems when a therapeutic PEGylated protein is being developed, because predictability of activity and manufacturing reproducibility are needed for regulatory approval. Enzymatic PEGylation of proteins is one route to overcome this limitation. Transglutaminases (TGase) are enzyme candidates for site-specific PEGylation. We use human interferon alpha 2a (IFN α2a) as a test case, and predict that the potential modification residues are Gln101 by computational approach as it contains 12 potential PEGylation sites. IFN α2a was PEGylated by Y shaped PEG40k-NH2 mediated by microbial transglutaminase. Our results show that the microbial transglutaminase mediated PEGylation of IFN α2a was site-specific only at the site of Gln101 in IFN α2a, yielding the single mono-conjugate PEG-Gln101-IFN α2a with a mass of 59 374.66 Da. Circular dichroism studies showed that PEG-Gln101-IFN α2a preserved the same secondary structures as native IFN α2a. As expected, the bioactivity and pharmacokinetic profile in rats of PEG-Gln101-IFN α2a revealed a significant improvement to unmodified IFN α2a, and better than PEGASYS.

Association of pre-pregnancy body mass index and gestational weight gain with neonatal outcomes in elderly gravida for second child / 中华围产医学杂志

Objective:To investigate the maternal pre-pregnancy body mass index (BMI) and gestational weight gain (GWG) during pregnancy at advanced maternal age for their second child at advanced maternal age, and to explore the relationship with neonatal outcomes.Methods:This study involved 1 965 women of advanced maternal age who delivered the second child in the Northwest Women's and Children's Hospital from July 1 to December 31, 2017. Clinical data of these women and their newborns were collected through the electronic medical record information system. According to pre-pregnancy BMI, all subjects were divided into four groups: underweight group (<18.5 kg/m 2, n=139), normal weight group (18.5-23.9 kg/m 2, n=1 342), overweight group (24.0-27.9 kg/m 2, n=404) and obese group (≥28.0 kg/m 2, n=80). According to the GWG standard recommended by the American Institute of Medicine (IOM) in 2009, they were also divided into three groups: inadequate GWG group ( n=478), normal GWG group ( n=884) and excessive GWG group ( n=603). Mann-Whitey U test, Chi-square test or Fisher's exact test were used as statistical methods. Effects of pre-pregnancy BMI and GWG on gestational age and birth weight of the newborns were analyzed by binary and multi-class logistic regression models. Results:The median pre-pregnancy BMI of the 1 965 women was 22.1 (20.3-23.9) kg/m 2 and patients with abnormal pre-pregnancy BMI accounted for 31.7% (623/1 965). Their median GWG was 13.0 (10.0-16.0) kg and 55.0% (1 081/1 965) of them were abnormal. Compared with normal pre-pregnant weight women, overweight and obesity subjects were associated with increased risks of preterm birth ( OR=2.100, 95% CI: 1.398-3.156), low birth weight infants (LBWI) ( OR=3.187, 95% CI: 1.892-5.367) and macrosomia ( OR=1.758, 95% CI: 1.182-2.614); pre-pregnancy underweight reduced the incidence of large for gestational age (LGA) infants ( OR=0.476, 95% CI: 0.236-0.960). Compared with the normal GWG group, the inadequate GWG group had increased risks of preterm birth ( OR=2.316, 95% CI: 1.530-3.505) and LBWI ( OR=1.850, 95% CI: 1.103-3.104), while the excessive GWG group showed increased risks of macrosomia ( OR=1.828, 95% CI: 1.225-2.726) and LGA infants ( OR=1.955, 95% CI: 1.448-2.640), but a reduced risk of LBWI ( OR=0.359, 95% CI: 0.193-0.667) and small for gestational age infants ( OR=0.452, 95% CI: 0.240-0.852). Conclusions:Both abnormal pre-pregnancy BMI (underweight, overweight and obese) and GWG (inadequate and excessive) have adverse effects on neonatal outcomes in women of advanced age in pregnancy for their second baby. Weight management should be addressed during the whole pregnancy, including both adjusting the pre-pregnancy BMI to normal range and maintaining reasonable GWG, so as to reduce potential adverse outcomes in newborns.